As far as I know there's only 2 Heros, Heros efasciatus and Heros severus and only efasciatus is a substrate spawner while severus is a mouthbrooder. The common Severum we see is esfasciatus and the red spot is not a hybrid between the two but a line bred version of the Gold strain. No different then how a Albino Tiger Oscar was essentially created. When you look up true hybrids you see they have no scientific name(Flowerhorns, Blood Parrots, Red Texas etc) while in the cichlid companions the Gold strain is identified as Heros efasciatus just like a Albino Tiger Oscar is identified as Astronotus ocellatus. Because in both instances the're just line bred versions of the original stain as you put it aberrations.
As for being more natural I'd say yes color morphs and line bred fish are more natural since hybrids tend to be infertile while line bred tend to be fertile. The more natural and easy breeding is for a fish the more natural the fish is in my opinion as it lends to them being viable in natural conditions. Plus we see color morphs in different localities, which means color morphs are natural occurring we just take a natural process one step further. I personally have no problem with hybrids but I love them for what they are just an example of a designer pet.
amphilophus trimaculatum - check out the tri mac in this NJAS facebook page. This fish was superb. It was owned by Mike Sheridan: https://www.facebook.com/NorthJerseyAquariumSociety?filter=2 Long before hybrids were created.
There are at least 5 Heros species (H. appendiculatus, efasciatus, notatus, sverus, spurious) and sp. "red shoulder"....plus lots of regional varients and underscribed ones that could be different species or not (depending on the icthyologist doing the description and their predilection for lumping or grouping).
Is a flowerhorn any more or less of a designer pet than say an electric red discus (which may or may not technically be a hybrid...depending on discus taxonomy's prevailing opinion this week).
And to go back to OP's question: Many designer fish are DESIGNED to have MORE COLOR than wild-type ones. That's the point
Trying to establish a bright-line distinction between line bred cichlids and hybrids ones, especially when the genetic make-up of fish like red severums, fancy discus, "neon" jewels, etc. is not known...just doesn't make sense.
Back to the OPs question.
My vote for most colorful natural cichlid is for Crenichichla sp. lugubris atabapo: http://www.cichlidae.com/gallery/species.php?id=2675
Matt